Sodium Carbonate → (1R,3aS,5aR,5bR,7aR,11aS,13aR,13bR)-benzyl 9-((E)-3-ethoxy-3-oxoprop-1-enyl)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysene-3a-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of (1R,3aS,5aR,5bR,7aR,11aR,13aR,13bR)-benzyl 5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-9-(trifluoromethylsulfonyloxy)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysene-3a-carboxylate, prepared as described in WO2011153315, (50 mg, 0.074 mmol), (E)-ethyl 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)acrylate (66.8 mg, 0.295 mmol), tetrakis(triphenylphosphine)palladium (8.54 mg, 0.0074 mmol) and sodium carbonate (39 mg, 0.369 mmol) in DME (1 mL) and water (1 mL) was heated to 100° C. for 1.5 hours. The reaction mixture was cooled to rt, extracted with ethyl acetate (3×5 mL). The extracts were combined, dried over sodium sulfate, filtered and concentrated under reduced pressure. The crude residue was purified by flash chromatography with 80-100% ethyl acetate/hexanes gradient to provide the title compound (20 mg, 43%). LCMS: m/e 627.55 (M+H)+, 3.60 min (method 6).

Provenance & Evidence